<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>CSS练习</title>
    <style>
        #id001{
            border: 1px red solid;
            font-size: 30px;
            color: red;
        }
        #id002{
            color: blue;
            border: 3px dashed blue;
        }
    </style>
</head>
<body>
    <div id="id001">div标签1</div>
    <div id="id002">div标签2</div>
<!--    <div id="id001">div标签2</div> 报错-->
<!--    <span id="id001">span标签1</span> 报错-->
</body>
</html>